Objective:To evaluate the efficacy and safety of once-daily tacrolimus extended-release capsules (OD-TAC) in pediatric liver transplant recipients after conversion from twice-daily tacrolimus (TD-TAC).Methods:A retrospective analysis was performed on pediatric liver transplant recipients at Tianjin First Center Hospital between January 2014 and December 2020 who were converted from TD-TAC to OD-TAC with a follow-up of at least 12 months. After conversion, all patients received OD-TAC monotherapy. The daily dose conversion ratio from TD-TAC to OD-TAC ranged from 2∶1 to 1∶2. Clinical data including demographics, tacrolimus dosage, trough concentrations, liver function, and adverse events were collected. Continuous variables with normal distribution were expressed as Mean±SD and compared using independent-samples t-test or ANOVA; non-normally distributed variables were expressed as median ( Q1, Q3) and compared using Mann-Whitney U or Kruskal-Wallis H tests. Categorical variables were expressed as frequency and percentage, and compared using χ 2 test or Fisher's exact test. P<0.05 was considered statistically significant. Results:A total of 290 children were enrolled, including 140 males (48.3%) and 150 females (51.7%). The median age at transplantation was 7.34 (6.03, 12.34) months, and the median time to conversion was 36 (29, 48) months post-transplant. Tacrolimus daily doses at 3, 6, and 12 months after conversion were slightly higher than before conversion, but without statistical significance (all P>0.05). Trough tacrolimus levels at 6 and 12 months after conversion were 2.34±1.02 μg/L and 2.23±1.07 μg/L, respectively, both lower than pre-conversion (2.77±1.43 μg/L), with statistical significance ( P=0.02 and P<0.01). Serum creatinine levels at 6 and 12 months post-conversion were 2.63±0.63 mmol/L and 2.76±0.68 mmol/L, respectively, both higher than before conversion (2.57±1.90 mmol/L, P<0.05). Triglyceride level at 12 months post-conversion was 0.87±0.25 mmol/L, significantly lower than pre-conversion (1.05±0.55 mmol/L, P<0.05). Two patients developed transient bilirubin elevation at 3 months, and another two developed transient triglyceride elevation at 6 months; all recovered without intervention. No new-onset diabetes was observed during follow-up. Thirteen patients experienced acute rejection. One patient (0.3%) died three years after conversion due to hepatic venous outflow obstruction, while all others survived. Conclusion:In pediatric liver transplant recipients, OD-TAC provides comparable efficacy and safety to TD-TAC.

Objective:To evaluate the efficacy and safety of once-daily tacrolimus extended-release capsules (OD-TAC) in pediatric liver transplant recipients after conversion from twice-daily tacrolimus (TD-TAC).Methods:A retrospective analysis was performed on pediatric liver transplant recipients at Tianjin First Center Hospital between January 2014 and December 2020 who were converted from TD-TAC to OD-TAC with a follow-up of at least 12 months. After conversion, all patients received OD-TAC monotherapy. The daily dose conversion ratio from TD-TAC to OD-TAC ranged from 2∶1 to 1∶2. Clinical data including demographics, tacrolimus dosage, trough concentrations, liver function, and adverse events were collected. Continuous variables with normal distribution were expressed as Mean±SD and compared using independent-samples t-test or ANOVA; non-normally distributed variables were expressed as median ( Q1, Q3) and compared using Mann-Whitney U or Kruskal-Wallis H tests. Categorical variables were expressed as frequency and percentage, and compared using χ 2 test or Fisher's exact test. P<0.05 was considered statistically significant. Results:A total of 290 children were enrolled, including 140 males (48.3%) and 150 females (51.7%). The median age at transplantation was 7.34 (6.03, 12.34) months, and the median time to conversion was 36 (29, 48) months post-transplant. Tacrolimus daily doses at 3, 6, and 12 months after conversion were slightly higher than before conversion, but without statistical significance (all P>0.05). Trough tacrolimus levels at 6 and 12 months after conversion were 2.34±1.02 μg/L and 2.23±1.07 μg/L, respectively, both lower than pre-conversion (2.77±1.43 μg/L), with statistical significance ( P=0.02 and P<0.01). Serum creatinine levels at 6 and 12 months post-conversion were 2.63±0.63 mmol/L and 2.76±0.68 mmol/L, respectively, both higher than before conversion (2.57±1.90 mmol/L, P<0.05). Triglyceride level at 12 months post-conversion was 0.87±0.25 mmol/L, significantly lower than pre-conversion (1.05±0.55 mmol/L, P<0.05). Two patients developed transient bilirubin elevation at 3 months, and another two developed transient triglyceride elevation at 6 months; all recovered without intervention. No new-onset diabetes was observed during follow-up. Thirteen patients experienced acute rejection. One patient (0.3%) died three years after conversion due to hepatic venous outflow obstruction, while all others survived. Conclusion:In pediatric liver transplant recipients, OD-TAC provides comparable efficacy and safety to TD-TAC.

Objective:To explore the effects of graft recipient weight ratio (GRWR) on the early prognosis (within 1 year after operation) of recipients of different ages after split liver transplantation (SLT) in children.Methods:From April 2015 to December 2022, the relevant clinical data were retrospectively reviewed for 188 children aged under 12 years undergoing initial SLT. Based upon operative age, they were assigned into groups of L (age≤18 months, 123 cases) and H (18 months< age≤12 years, 65 cases). Draw receiver operating characteristic (ROC) curves for predicting survival rates in H and L groups using GRWR and determine the cut-off value, and subgroup dassification was based the value. Compare the general condition, intraoperative condition, postoperative condition, and major complications of recipients. Follow-ups were conducted until 12 months post-SLT, death or retransplantation within 12months post-SLT. Kaplan-Meier survival rate analysis was utilized for comparing early postoperative survival rate of recipient/graft. The incidence of major early postoperative complications was examined by χ2 test or Fisher exact probability method. Results:The survival rate of recipients at Month 12 post-SLT was 92.6% (174/188), and graft survival rate was 91.0% (171/188). The survival rate of recipients in group L at Month 12 post-SLT was 94.3% (116/123), and graft survival rate was 92.7% (114/123). The GRWR value determined of 3.1 %. According to the level of GRWR, group L was divided into groups of L-L (GRWR≤3.1%, 36 cases) and L-H (GRWR>3.1%, 87 cases) while group H groups of H-L (GRWR≤3.1%, 55 cases) and H-H (GRWR>3.1%, 10 cases). The survival rates of recipients in groups L-L/L-H were 88.9% (32/36) and 96.6% (84/87) at Month 12 post-SLT. Inter-group difference was not statistically significant ( P=0.077). Graft survival rates were 83.3% (30/36) and 96.6% (84/87 ). Inter-group difference was statistically significant ( P=0.007). The intraoperative cold ischemia time were 479.0 (194.0, 593.0) min and 204.0 (122.0, 495.0) min in groups L-L/L-H. Inter-group difference was statistically significant ( P=0.002 ). The incidence of hepatic artery thrombosis were 13.9 % (5/36) and 2.3 % (2/87) in groups L-L/L-H. Inter-group difference was statistically significant ( P=0.036). The survival rate of recipients in group H at Month 12 post-SLT was 89.2% (58/65), and graft survival rate was 87.7% (57/65). No significant inter-group difference existed during surgery ( P>0.05 ). The survival rates of recipients in group H-L/H-H at Month 12 post-SLT were 92.7 % (51 /55) and 70.0 % (7/10 ). Inter-group difference was statistically significant ( P=0.019). Graft survival rates were 90.9% (50/55) and 70.0% (7/10). Inter-group difference was statistically significant ( P=0.036). No significant inter-group difference existed in the incidence of complications ( P>0.05) . Conclusion:During pediatric SLT, recipients of different ages have different requirements for GRWR. GRWR≤3.1 % implies poor early prognosis of recipients aged ≤18 months and GRWR>3.1% is associated with poor early prognosis of recipients aged between 18 months and 12 years.

Objective:To explore the risk factors and treatments of portal vein thrombosis (PVT) in children after pediatric living donor liver transplantation (pLDLT) .Method:From January 2014 to December 2021, the relevant clinical data were retrospectively reviewed for 975 LDLT children at Department of Pediatric Organ Transplantation of Tianjin First Central Hospital. Based upon the postoperative occurrence of PVT, they were assigned into two groups of PVT (19 cases) and non-PVT (956 cases). Univariate and multivariate analyses were performed for screening the risk factors of PVT post-LDLT and discussing the managements and prognoses of PVT.Result:Among them, overall incidence of PVT post-LDLT was 1.9% (19/975), and median time for an initial occurrence of PVT 8 (1-495) day. Single-factor analysis indicated that donor height ( P=0.014), operative duration ( P=0.002) and vascular interposition ( P=0.001) were correlated with the occurrence of postoperative PVT post-pLDLT. Multifactorial analysis revealed that operative duration ( P=0.008) and vascular interposition ( P<0.01) were independent risk factors for PVT post-pLDLT. For 19 cases of postoperative PVT, the measures included surgical thrombectomy (8 cases), urokinase thrombolysis plus warfarin anticoagulation (3 cases), interventional treatment (3 cases), warfarin anticoagulation (4 cases) and retransplantation (1 cases). After treatment, the outcomes were a disappearance of PVT (15 cases), symptomatic improvement (2 cases) and unrelated mortality (2 cases) . Conclusion:During pLDLT, intraoperative placement of blood vessels and operative duration are independent risk factors for the occurrence of PVT. Timely standardized treatment may achieve satisfactory therapeutic outcomes.

Objective:To study the impact of donor left hepatic vein classification and the reconstruction methods on hepatic venous outflow obstruction (HVOO) after pediatric living-donor liver transplantation using left lateral liver segments.Methods:A retrospective study was performed on the clinical data of 653 children recipients who underwent living-donor liver transplantation with left lateral liver segments from January 2014 to December 2020 at Tianjin First Central Hospital. There were 309 males and 344 females, aged 7.0 (6.0, 10.0) months, with an age range of 3-121 months. Based on the left hepatic vein on preoperative donor enhancement CT as well as the intraoperative reconstruction methods, the recipients were divided into 3 groups: type Ⅰ group ( n=514), anastomosis using a single opening was performed directly between the donor and the recipient; type Ⅱ group ( n=118), angioplasty was performed on two adjacent recipient venous orifices before anastomosis, and type Ⅲ group ( n=21), an interposition vessel was anastomosed to two widely spaced openings or the two veins were anastomosed separately. The preoperative general status of the patient, postoperative HVOO incidences, and graft and recipient survival rates were compared among the three groups. The patients were followed up by outpatient reexamination or telephone. Results:Graft to recipient weight ratio in the type Ⅲ group was smaller than that in the type Ⅰ group and the type Ⅱ group ( P<0.05). For all the 653 patients, the incidence of postoperative HVOO was 4.59% (30/653), with the incidences of HVOO in the 3 groups of patients were 4.1% for the type Ⅰ group (21/514), 5.1% for the type Ⅱ group (6/118), and 14.3% for the type Ⅲ group (3/21), respectively. There was no significant difference among the groups ( P>0.05). The recipient cumulative survival rates at 1 and 3 years after surgery in the type I group were 97.8% and 97.0%, and the corresponding rates in the type Ⅱ group were 96.5% and 94.2%, and in the type Ⅲ group were 94.1% and 86.9%, respectively. There was a significant difference between the type Ⅰ and type Ⅲ groups ( P=0.048). The graft cumulative survival rates at 1 and 3 years in the type Ⅰ group were 97.4% and 96.9%, and the corresponding rates in the type Ⅱ group were 94.9% and 92.5%, and in the type Ⅲ group were 94.1% and 86.9%, respectively. The difference in the postoperative graft cumulative survival rates between the type Ⅰ group and type Ⅱ group was significant ( P=0.044). Conclusions:The anatomy of the left hepatic vein supplying the left lateral liver segment was highly variable, and the majority of the variations could be reconstructed. A reasonable reconstructive method could reduce the incidence of postoperative HVOO and improved the outcomes of the graft.